The present invention is generally related to water treatment systems and methods and, more particularly, to the treatment of water near its point of use using laser technology.
The microbiologic quality of water used in dental treatment must be improved. The medical profession, and in particular the dental industry and the medical research community, are taking steps to improve the quality of water used in patient care. Dental unit waterlines (the tubes that connect the high-speed handpiece, air/water syringe and ultrasonic scaler to the water supply) have been shown to harbor a wide variety of microorganisms including bacteria, fungi, and protozoans. These microorganisms colonize and replicate on the interior surfaces of the waterline tubing, inevitably resulting in adherent heterogeneous microbial accumulations termed xe2x80x9cbiofilms.xe2x80x9d Biofilms, once formed, serve as a reservoir significantly amplifying the numbers of free-floating microorganisms in water exiting the waterlines.
Dental unit water systems currently designed for general dental practice are incapable of efficiently and/or effectively delivering water of an optimal microbiologic quality. The ADA (American Dental Association) Council on Scientific Affairs has recommended (as adopted by the American Dental Association Board of Trustees, Dec. 13, 1995) that xe2x80x9can ambitious and aggressive course to encourage industry and the research community to improve the design of dental equipment so that by the year 2000, water delivered to patients during nonsurgical dental procedures consistently contains no more than 200 colony forming units per milliliter (cfu/ml) of aerobic mesophilic heterotrophic bacteria at any point in time in the unfiltered output of the dental unit; this is equivalent to an existing quality assurance standard for dialysate fluid that ensures the fluid delivery systems in hemodialysis units have not been colonized by indigenous waterborne organisms.xe2x80x9d
An illustration provided by Clinical Research Associates (CRA) in its March 1997 newsletter best illustrates the problem with respect to waterline contamination. Referring to FIG. 1, water may arrive at a building relatively microbe-free, at about 2 cfu/ml, because of the large diameter water delivery piping A. As water lines narrow within the building B (within inches in diameter) the microbe count increases to about 10 cfu/ml. At the junction box D within the dental unit (with tubing rated at less than an inch in diameter) the count is about 10,000 cfu/ml. After water has traveled about 10 feet within the dental station to the control center E, the count can go up to about 400,000 cfu/ml. Finally, at the sterile handpiece F and non-sterile air/water supply G (the sources of water into a patient""s mouth) the microbe count entering the patients mouth can be 100,000 to 200,000 cfu/ml.
At the present time, commercially available options for improving dental unit water quality are limited and will involve some additional expense. They include: point-of-use filters; independent water reservoirs; chemical treatment regimens; dissasembly and sterilization, and daily draining and air purging regimens.
Dental unit water line filters may physically stop some bacteria from progressing through dental units, but the effectiveness of their use has not seen much research to clearly demonstrates their effectiveness, and microorganisms are capable of developing within the waterline or apparatus that exists after the filter""s location. Furthermore, overuse or failure of a filter can lead to even higher levels of microorganisms.
Separate water systems allow dentists to disconnect their dental unit from the municipal water supply and replace it with a sterile water bottle. Such systems are most advantages to practitioners who are remodeling or opening up a new office due to the extensive plumbing requirements; however, microorganism growth within the resident system cannot be prevented.
Chemical approaches to disinfecting dental unit water lines have enjoyed varying success. One approach is the use of iodine to disinfect waterlines. The safety and efficacy of chemical disinfection protocols have not been sufficiently validated in the past; therefore the Council has strongly discouraged dentists from treating their dental unit waterlines chemically. In particular, the Council has warned against the use of glutaraldehyde in treatment-water delivery systems to meet the goals set out in the ADA""s Statement on Dental Unit Waterlines. Glutaraldehyde is a recognized health hazard; it is a known dermal, mucosal, respiratory and systemic irritant that, as stated on its labeling, is only intended for use in closed containers. In addition to the potentially serious adverse health effects that may be associated with glutaraldehyde when used in dental unit waterlines, such use will essentially fix or xe2x80x9cgluexe2x80x9d the biofilm matrix to the surface of the waterline, leaving an ideal environment for microbial re-colonization.
Entire dental unit waterline sterilization is another technique being investigated. Such methods would require the dissasembly and sterilization of components within the dental station (in particularly the water delivery portions) that can be heat sterilized. Although such a system should be convenient for dentists because of their use of heat sterilization on handpieces and other equipment, such methods would require much added labor for dental office staff to effectively disassemble, sterilize, and reassemble waterlines.
Draining and air purging regimes, although the simplest method to employ, does not directly target the elimination of biofilm within system tubing.
Some combination of the above strategies may be necessary to control, biofilm formation and to achieve the desired level of water quality. To date, however, there is insufficient data to establish the effectiveness of available methods. Many of the described methods do not directly address microorganism buildup that may occur within waterlines throughout the day. Furthermore, many of the described methods may not be cost effective for the industry. Therefore a wider range of alternatives and adjuncts to the above listed options is desirable. It is further desirable that treatment in waterlines occur at a point closest to the xe2x80x9cpoint of usexe2x80x9d in order to ensure a higher probability of water treatment system effectiveness.
The present invention addresses the need for more effective and cost efficient water treatment. The present invention provides for the laser treatment of water near its point of use within a waterline and/or at a waters source.
As described in an embodiment of the invention, water enters a treatment area, such as a junction box, from waterline tubing wherein it is subjected to light from laser light as it passes through a treatment area, wherein microorganisms contained within said water are reactive to the light and are killed. The water is then provided to a point of use.
In another embodiment of the invention, the treatment area may be a junction box having an entry point for receiving water from input tubing connected to the input portion of the junction box. A fiber optic line and/or laser source can be optically coupled to the junction box for delivery of light treatment into the junction box. An exit point then provides water passing through the junction box to a point of use.
In another embodiment of the invention, the junction box is integrated within and provided near the distal end (head) of a dental handpiece. Input waterline tubing carries water from the control panel of a dental system to the handpiece where the tubing is connected to an input portion of the junction box. Fiber optic cabling and/or a laser can be optically coupled to the junction box for delivery of light treatment into the junction box. The tubing and/or passageway within the head of the handpiece can be connected to the output portion of the junction box. An exit port within the head can then, provide water to its intended point of use.
In yet another embodiment of the invention, the head can be removably connected to the handpiece and/or junction box.
Another embodiment of the invention can provide a beam directing mechanism, such as a splitter or switching mechanism, for directing light between an exit port in the dental instrument and/or the water treatment area or junction box within the hand piece and a treatment area at a point of use (e.g., a dental patients mouth).